<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			function fn1 (n) {
				var sum = 0;
				for (var i=1;i<=n;i++) {
					sum = sum + i;
				}
				alert(sum)
			}
			fn1(101)
		</script>
	</body>
</html>
